/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/**
 * This class includes code modified from Eclipse Collections project.
 *
 * <p>Copyright: 2021 Goldman Sachs
 *
 * <p>Project page: https://www.eclipse.org/collections/
 *
 * <p>License: https://github.com/eclipse/eclipse-collections/blob/master/LICENSE-EDL-1.0.txt
 */
package org.apache.iotdb.tsfile.utils;

import java.util.Arrays;

public class ByteArrayList {

    private static final byte[] DEFAULT_SIZED_EMPTY_ARRAY = {};
    private static final byte[] ZERO_SIZED_ARRAY = {};
    private static final int MAXIMUM_ARRAY_SIZE = Integer.MAX_VALUE - 8;

    protected int size;
    protected transient byte[] items = DEFAULT_SIZED_EMPTY_ARRAY;

    public ByteArrayList() {
    }

    public ByteArrayList(int initialCapacity) {
        this.items = initialCapacity == 0 ? ZERO_SIZED_ARRAY : new byte[initialCapacity];
    }

    private void ensureCapacityForAdd() {
        if (this.items == DEFAULT_SIZED_EMPTY_ARRAY) {
            this.items = new byte[10];
        } else {
            this.transferItemsToNewArrayWithCapacity(this.sizePlusFiftyPercent(this.size));
        }
    }

    private int sizePlusFiftyPercent(int oldSize) {
        int result = oldSize + (oldSize >> 1) + 1;
        return result < oldSize ? MAXIMUM_ARRAY_SIZE : result;
    }

    private void transferItemsToNewArrayWithCapacity(int newCapacity) {
        this.items = this.copyItemsWithNewCapacity(newCapacity);
    }

    private byte[] copyItemsWithNewCapacity(int newCapacity) {
        byte[] newItems = new byte[newCapacity];
        System.arraycopy(this.items, 0, newItems, 0, Math.min(this.size, newCapacity));
        return newItems;
    }

    public boolean add(byte newItem) {
        if (this.items.length == this.size) {
            this.ensureCapacityForAdd();
        }
        this.items[this.size] = newItem;
        this.size++;
        return true;
    }

    public boolean addAll(byte... source) {
        if (source.length < 1) {
            return false;
        }
        this.copyItems(source.length, source);
        return true;
    }

    private void copyItems(int sourceSize, byte[] source) {
        int newSize = this.size + sourceSize;
        this.ensureCapacity(newSize);
        System.arraycopy(source, 0, this.items, this.size, sourceSize);
        this.size = newSize;
    }

    public void ensureCapacity(int minCapacity) {
        int oldCapacity = this.items.length;
        if (minCapacity > oldCapacity) {
            int newCapacity = Math.max(this.sizePlusFiftyPercent(oldCapacity), minCapacity);
            this.transferItemsToNewArrayWithCapacity(newCapacity);
        }
    }

    public byte[] toArray() {
        byte[] newItems = new byte[this.size];
        System.arraycopy(this.items, 0, newItems, 0, this.size);
        return newItems;
    }

    public byte removeAtIndex(int index) {
        byte previous = this.get(index);
        int totalOffset = this.size - index - 1;
        if (totalOffset > 0) {
            System.arraycopy(this.items, index + 1, this.items, index, totalOffset);
        }
        --this.size;
        this.items[this.size] = (byte) 0;
        return previous;
    }

    public byte get(int index) {
        if (index < this.size) {
            return this.items[index];
        }
        throw new IndexOutOfBoundsException("Index: " + index + " Size: " + this.size);
    }

    public void clear() {
        Arrays.fill(this.items, 0, size, (byte) 0);
        this.size = 0;
    }

    public int size() {
        return this.size;
    }
}
